Bobbins for the Interchangeable Drop Spindle. 
Listing is for 1 bobbin.
 
Top diameter 1.25"
Length 3"
Friction fit to spindle shaft
 
Available in 3 packs here: 3 Pack
 
3D printed from PLA bioplastic
This item is print to order to reduce waste and may have a couple of days of lead time.